Golf is a popular sporting activity played by millions of people worldwide. Especially popular are training tools designed to improve a player's technical skill. One important skill is the ability to control the relationship between the golf club and the leading arm during a swing.
Variations in the leading arm-to-club relationship at impact result in different golf ball velocities and trajectories. This is due to the centripetal force urging the club to seek an in-line relationship with the leading arm. As the moment of impact approaches, if the club head is lagging behind the leading arm, the club head will experience an accelerating force urging it to catch up and become in-line with the leading arm. This force counters the deceleration force of the golf ball at impact and, as a result, power and control are highest. The opposite is true if the club head moves ahead of the leading arm prior to impact. In this case, centripetal force urges the leading club head to slow down and power loss occurs.
Thus, there exists an ongoing need for a training tool that provides feedback about the relationship between the leading arm and the golf club during a swing. More precisely, the tool should enable the user to experiment with a continuous range of variations in this relationship so as to observe the differences in the resulting ball behaviors. Advantageously, the tool is adjustable, making it equally effective for golfers of varying grip styles and arm thicknesses.
U.S. Pat. No. 8,128,507 to Chuck discloses an arching guide arm that rests against the golfer's forearm. With Chuck's device, the user is unable to select the exact relationship between the club and the leading arm. The user can only choose from two possible relationships between the leading arm and the club—one with the club lagging, and one with the club in front of the leading arm. Because Chuck's guide arm is only adjustable vertically, using a lagging club head requires the guide arm to separate from the forearm during the backswing, pass under the arm and become in front of the arm at impact. For each of these two options, the exact relationship of the club is at the mercy of the forearm girth and grip style of the individual user.
U.S. Pat. No. 5,009,426 to Cox discloses a guide that rests against the user's trailing arm. Cox's device provides feedback about the trailing arm in relation to the club. However, because the relationship between the leading and trailing arms can vary, controlling the trailing arm-to-club relationship does not necessarily result in controlling the leading arm-to-club relationship.